During the last two decades, designers of tools and sporting equipment have turned their attention to the health, safety and efficiency consequences of implement handle design. Conventional handles have a straight configuration, aligned along the longitudinal axis of the implement's shaft. The classic fly fishing rod handle is a round, cigar-shaped handle affixed in such a straight configuration relative to the fly fishing rod. The negative effects of the conventional handle are particularly visible in the fly fishing context, which involves hours of repetitive fly casting motions.
In U.S. Pat. No. 4,038,719, Bennett explains the deleterious effects of a handle in a straight configuration. Rather than being adapted to the form and function of the human arm, wrist and hand, such a handle wastes muscle energy and creates physical stressors by requiring the person to adapt to the handle. Thus, when picking up an implement with a straight configuration handle, a person naturally cocks the wrist to a tension-producing angle. Furthermore, use of such a handle to generate the intended action of the implement requires unnatural wrist rotation throughout the range of motion. The handle is therefore fatiguing, wasteful of energy, and causes unnecessary localized joint stress which can wear away at the protective soft tissue and lead to debilitating injuries such as carpal tunnel syndrome. The handle, by requiring that the wrist bend repeatedly while the implement is in use, interferes with the wrist's natural shock absorption capabilities and can restrict blood flow to the fingers.
Several prior art references have described products claiming the ergonomic benefits of handles angled to overcome the problems associated with the straight configuration. U.S. Pat. No. 4,038,719, Bennett, describes a handle which is disposed at a preferred angle of 19-degrees to the longitudinal axis of the shaft, bending the handle rather than the wrist. This angle takes advantage of the natural angle of wrist flexion and extension in tasks such as hammering or sweeping. The handle is also oval in shape with a slight taper, in an attempt to conform to the hand's natural grip configuration.
The handle described by Bennett does not accommodate the knuckle position of the bent fingers. However, it is known in the art to modify the Bennett configuration by adding a second angle conforming to the contour of the knuckles so as to accommodate the knuckles and thereby alleviate friction between the knuckles and the shaft.
The Bennett handle has been adapted for use on a fishing rod. An earlier version of the present invention also included an approximately 19-degree angle such as found in the Bennett handle. However, the large angular disposition of the handle relative to the longitudinal axis of the fly fishing rod resulting from the use of such handle designs were found to interfere with the fly fishing rod's function when using the fly rod in a normal manner.
The primary 19-degree angle provided by Bennett causes the fishing rod to cast improperly, in large part because the angle of attack in the forecast brings the rod and rod tip too far down towards the horizontal and beyond, causing a caster to "dump" the forecast so that the line goes into the water in a pile rather than extending out over the water. A caster would have to make abnormal casting motion adjustments to make effective use of a fishing rod with a Bennett handle. Furthermore, the angle on the handle causes the reel seat to protrude at an extreme angle. The resulting fly rod configuration (i) causes the normal slack line, between the caster's line hand, to catch on the rod butt of the reel seat, (ii) does not allow for the use of an extension rod butt used for landing large fish, i.e., those over five pounds, (iii) leaves insufficient area along the rod's longitudinal axis for the user to properly grip the fly rod, and (iv) does not fit into a conventional fly rod case. Additional problems arise because the Bennett handle with its extreme angle cannot be retrofitted on existing fly rods having straight elongated shafts without cutting the rod shaft, and cannot be formed from cork because the cork lacks sufficient strength to support the rod shaft once it has been cut.
U.S. Pat. No. 5,125,130, Stanish, discloses a second handle configuration utilizing a larger angular distortion of 26 to 35 degrees. This handle has a two-membered gripping portion to further reduce wrist stressors, and allows more relaxed and accurate implement utilization. However, the large angular disposition disclosed by Stanish similarly would interfere with normal fly casting technique and reel configurations.